Storing names and standard SPDX identifiers for common open source licences.

§1. This is little more than a dictionary of IDs to records about the standard set of open source licences maintained by SPDX. 

typedef struct open_source_licence {
    struct text_stream *SPDX_id;
    struct text_stream *name;
    int deprecated;
    CLASS_DEFINITION
} open_source_licence;

dictionary *SPDX_licence_identifiers = NULL;

void LicenceData::new_licence(text_stream *id, text_stream *name, int deprecated) {
    open_source_licence *L = CREATE(open_source_licence);
    L->SPDX_id = Str::duplicate(id);
    L->name = Str::duplicate(name);
    L->deprecated = deprecated;
    if (SPDX_licence_identifiers == NULL)
        SPDX_licence_identifiers = Dictionaries::new(256, FALSE);
    Dictionaries::create(SPDX_licence_identifiers, L->SPDX_id);
    Dictionaries::write_value(SPDX_licence_identifiers, L->SPDX_id, L);
}

open_source_licence *LicenceData::from_SPDX_id(text_stream *id) {
    if (SPDX_licence_identifiers == NULL) return NULL;
    if (Dictionaries::find(SPDX_licence_identifiers, id) == NULL) return NULL;
    return Dictionaries::read_value(SPDX_licence_identifiers, id);
}